Green beans (phaseolus vulgarism) are a tender annual that grows in U.S. Department of Agriculture Hardiness Zones 3 through 10. Because they are sensitive to frost, plant green beans after the last chance of frost in the late spring. Although green beans can be started indoors four weeks before the last expected frost date for an earlier harvest, it is much better to wait and direct sow seeds outdoors because beans do not grow well when transplanted.
Selecting a Variety
Green beans come in two types: pole and bush. Pole beans require a sturdy trellis for support, which can be difficult, although not impossible, to erect around a container. Most container gardeners opt for bush varieties that require no additional support. When shopping for seeds, look for a description that includes the word bush. For best results when growing beans in a 12- to 18-inch container, opt for dwarf varieties such as the Prince Dwarf green bean or Delinel Green Bean, which feature more compact root systems and plants while offering large harvests.
Almost any green bean can be grown in a large container. One that is 18 to 24 inches wide is sufficient to contain a few standard plants. (Five-gallon food-grade buckets work well as green bean containers.) Regardless of the container's size, make sure it has at least six half-inch drainage holes at the bottom. Green beans will not tolerate poorly draining soils.
Containers dry out much faster than ground soil. Plan to water one to two times daily in the hottest part of summer.
Planting in a Container
- After the last chance of frost has passed, fill a container to about 2 inches below the top with equal parts topsoil, compost and vermiculite or perlite.
- Dig several holes 1 inch in diameter, 1 inch deep and 6 inches apart. The number of plants that will fit in the container will depend on its shape and size. Do not plant any seeds closer than 4 inches from the side of the container as this will not allow enough room for roots to grow.
- Place one seed in each hole. Water well and keep the soil moist until the seeds sprout. Throughout the growing season, continue watering any time the soil is dry 1 inch below the surface.
- Place the container in full sun; green beans will not produce beans if they receive anything less than six to eight hours of light per day.
- Refrain from fertilizing at planting time because compost exists in the soil mixture. A general liquid vegetable fertilizer can be applied once a month by adding 1 tablespoon of fertilizer to 1 gallon of water per container.
Do not over-fertilize. Adding too much can lead to excess nitrogen in the soil, leading to big bushy plants with very few green beans.
Once they start producing, green beans must be harvested daily. Allowing beans to stay on the vine will trigger the plant to stop producing. Use one hand to secure the vine and gently pull beans off with the other. Pick beans when the plant is completely dry to avoid spreading bean bacterial blight.
Never pull or tug on vines; they are delicate and will break easily.